The disposable plastic microcuvette contains reagents and through capillary action is filled with approximately 10 µL of sample. Capillary, venous, or arterial blood may be used for testing. The microcuvette is placed into either the HemoCue Hb 201+ Analyzer, Hb 201 DM Analyzer or B-Hemoglobin photometer where the absorbance is measured and the hemoglobin level is determined. The reagents within the microcuvettes are moisture sensitive. Replace the cap immediately after microcuvettes are removed from the container.